I came across an advertisement about a product that can charge your mobile on your bicycle during a 15 minutes travel. I thought it was a cool innovative idea that will serve well the millions of rural people in India and China. I was disappointed when I visited the company’s website as it carried no information about the product. Doing a web search revealed this was a concept showcased by Motorola in January 2007 itself. Anyways this is definitely an useful innovation for millions.
And if you are DIY type, doing this should not be very difficult or expensive. It can be done with an ordinary cycle-light dynamo and some circuitry to match and stabilize the output voltage.